What preventive screening is recommended for a 45-year-old transgender female on estrogen therapy (ethinyl estradiol), with a history of breast augmentation and vaginoplasty, and no family history of cancer?

Breast Cancer Screening for a 45-Year-Old Transgender Female on Estrogen Therapy

Breast cancer screening with mammography is recommended for this 45-year-old transgender female who has been on estrogen therapy for 4 years. 1

Risk Assessment and Screening Rationale

• The patient is 45 years old with 4 years of estrogen therapy (ethinyl estradiol), approaching the 5-year threshold that guidelines use for risk stratification in transgender women 1
• The American College of Radiology (ACR) recommends that digital breast tomosynthesis or mammography screening "may be appropriate" for average-risk transgender women who are 40 years or older with past or current hormone use for 5 years 1
• While the patient has not yet reached the full 5-year threshold of hormone therapy, her age (45) and approaching the 5-year mark make breast cancer screening the most appropriate preventive measure at this time 1
• The patient has had breast augmentation, which does not preclude the need for screening but may require special positioning techniques during mammography 1

Screening Recommendations Based on Guidelines

• For transgender women on feminizing hormone therapy, breast cancer risk increases compared to cisgender men but remains lower than cisgender women 1
• A Dutch cohort study showed increased breast cancer risk in transgender women receiving gender-affirming hormone therapy compared to cisgender men (SIR: 46.7) 1
• Different guidelines offer slightly varying recommendations:
  • Fenway Health: Annual screening mammography starting at age 50 for those with ≥5 years of hormone therapy 1
  • UCSF Center of Excellence: Biennial screening mammography starting at age 50 for those with ≥5 years of hormone therapy 1
  • Endocrine Society: Recommends transgender women undergo breast cancer screening similar to cisgender women (typically starting at age 40) 1
  • ACR: For those 40 years or older with ≥5 years of hormone use, digital breast tomosynthesis or mammography screening may be appropriate 1

Other Screening Considerations

• Cervical cancer screening: Not applicable as the patient has had vaginoplasty but no cervix 1
• Colon cancer screening: Not yet indicated as the patient is 45 with no family history of colon cancer (typically starts at age 45-50) 1
• Prostate cancer screening: Generally not recommended for transgender women on long-term estrogen therapy due to significantly reduced risk 1
• Osteoporosis screening: Not typically recommended until age 65 in women without specific risk factors 1

Clinical Pearls and Caveats

• Exogenous estrogen therapy is associated with increased breast cancer risk in both cisgender and transgender populations 1, 2
• Breast tissue in transgender women on hormone therapy develops ducts, lobules, and acini histologically identical to cisgender females and should not be referred to as gynecomastia 1
• The presence of breast implants requires special mammographic techniques but does not preclude screening 1
• For patients with breast implants who cannot undergo standard mammography, MRI may be considered as an alternative screening method 1
• Digital breast tomosynthesis (3D mammography) may provide better visualization in patients with dense breast tissue, which can develop in transgender women on estrogen therapy 1

Monitoring and Follow-up

• Once the patient reaches the 5-year threshold of hormone therapy, regular breast cancer screening should be maintained according to guidelines 1
• Annual clinical breast examinations are also recommended, though self-breast examination is not strongly supported by evidence 3
• Consider reassessing breast cancer risk periodically, especially if family history changes or if hormone regimens are modified 1